Abstract: A xenotime phosphate protective overlayer (22) for protecting a ceramic material (24) from a high temperature, moisture-containing environment. Yttrium phosphate may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic non-oxide material, such as silicon carbide or silicon nitride, an oxygen barrier layer (34) is disposed between the xenotime phosphate coating and the non-oxide material. Such a protective overlayer may be used for an article having a ceramic matrix composite substrate.

Abstract: A hybrid ceramic structure (10), for use in high temperature environments such as in gas turbines, is made from an insulating layer (12) of porous ceramic that is thermally stable at temperatures up to 1700° C. bonded to a high mechanical strength structural layer (8) of denser ceramic that is thermally stable at temperatures up to 1200° C., where optional high temperature resistant adhesive (9) can bond the layers together, where optional cooling ducts (11) can be present in the structural layer and where hot gas (14) can contact the insulating layer (12) and cold gas (15) can contact the structural layer (8).

Abstract: A composite material (10) formed of a ceramic matrix composite (CMC) material (12) protected by a ceramic insulating material (14). The constituent parts of the insulating material are selected to avoid degradation of the CMC material when the two layers are co-processed. The CMC material is processed to a predetermined state of shrinkage before wet insulating material is applied against the CMC material. The two materials are then co-fired together, with the relative amount of shrinkage between the two materials during the firing step being affected by the amount of pre-shrinkage of the CMC material during the bisque firing step. The shrinkage of the two materials during the co-firing step may be matched to minimize shrinkage stresses, or a predetermined amount of prestress between the materials may be achieved. An aluminum hydroxyl chloride binder material (24) may be used in the insulating material in order to avoid degradation of the fabric (28) of the CMC material during the co-firing step.

Abstract: A hybrid ceramic structure (10), for use in high temperature environments such as in gas turbines, is made from an insulating layer (12) of porous ceramic that is thermally stable at temperatures up to 1700° C. bonded to a high mechanical strength structural layer (8) of denser ceramic that is thermally stable at temperatures up to 1200° C., where optional high temperature resistant adhesive (9) can bond the layers together, where optional cooling ducts (11) can be present in the structural layer and where hot gas (14) can contact the insulating layer (12) and cold gas (15) can contact the structural layer (8).

Abstract: A composite (20) has a matrix (10), preferably of ceramic, interspersed with reinforcement structures (12), preferably ceramic fibers, coated with a material (14) selected from ZrGeO4, HfGeO4 and CeGeO4, where the composite can be used as a component in high temperature turbines.

Abstract: A xenotime phosphate protective overlayer (22) for protecting a ceramic material (24) from a high temperature, moisture-containing environment. Yttrium phosphate may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic non-oxide material, such as silicon carbide or silicon nitride, an oxygen barrier layer (34) is disposed between the xenotime phosphate coating and the non-oxide material. Such a protective overlayer may be used for an article having a ceramic matrix composite substrate.

Abstract: A vane assembly for a turbine assembly includes an inner endcap, an outer endcap, and a body. The body includes a metallic core assembly, a ceramic shell assembly and a support assembly. The metallic core assembly is coupled to the inner and outer endcaps and bears most of the mechanical loads, including aerodynamic loads. The ceramic shell bears substantially all of the thermal stress placed on the vane assembly. The support assembly is disposed between the metallic core assembly and said ceramic shell assembly and is coupled to the metallic core assembly.

Abstract: A dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises an aerogel base and ceramic skin overlaying the aerogel base. The aerogel base comprises a low density ceramic material. A method of fabricating a dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises the steps of preparing a colloidal dispersion of a ceramic material in a medium, increasing a concentration of the colloidal dispersion by evaporation to create a suspension, and placing the suspension in a mold. The suspension is solidified to form an aerogel and the aerogel is joined to a ceramic skin.